Field of the Invention
The present invention relates to a substrate treating apparatus and a substrate treatment method for discharging a treatment solution from a nozzle to a thin-plate microelectronic substrate (hereinafter, merely referred to as a “substrate”) such as a semiconductor wafer and a glass substrate for liquid crystal display to perform a predetermined treatment.
Description of Background Art
In the conventional process of manufacturing a semiconductor device or the like, substrate treatments such as a cleaning treatment and a resist coating treatment are performed by supplying a substrate with various treatment solutions such as deionized water, a photoresist solution, and an etching solution. Widely used as an apparatus that performs the solution treatment using such treatment solutions is a substrate treating apparatus that discharges a treatment solution to the surface of a substrate from a nozzle while horizontally rotating the substrate.
Such a substrate treating apparatus checks whether the treatment solution is discharged from the nozzle by checking an output of a flowmeter or the operation of a pump. As means for determining the presence or absence of a discharge more reliably, for example, Japanese Patent Application Laid-Open No. 11-329936 (1999) proposes that imaging means such as CCD camera, provided in a substrate treating apparatus, directly monitors a discharge of a treatment solution from a nozzle.
When imaging means directly monitors a discharge of a treatment solution from a nozzle, the background during imaging varies depending on the type of a to-be-treated substrate. In typical cases, a pattern is formed on the surface of a substrate by depositing various films such as a resist film and an insulating film thereon. The reflectance of the surface of the substrate varies greatly depending on the type of such a film or the formed pattern, which may result in a different background during imaging depending on the type of a to-be-treated substrate. If the same type of film is formed, in the etching treatment with, for example, hydrofluoric acid, the corrosion of the film may progress with a lapse of treatment time, changing the reflectance of the surface of the substrate. This increases the noise of an image captured by imaging means due to various factors such as the type of a film deposited on the substrate surface, the formed pattern, and the details of the treatment, so that a discharge of the treatment solution from the nozzle cannot be detected accurately.